OFFSET
4,2
FORMULA
For n >= 7, a(n) = (n^4-18*n^3+143*n^2-486*n+672)/24.
a(n) = sum(A007318(n-k, k), k=0..4), n >= 7. - Johannes W. Meijer, Aug 11 2013
CROSSREFS
KEYWORD
nonn
AUTHOR
Clark Kimberling, May 02 2000
STATUS
approved